﻿/*
 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * common internal and external API header
 */

#ifndef AVUTIL_COMMON_H
#define AVUTIL_COMMON_H

#if defined(__cplusplus) && !defined(__STDC_CONSTANT_MACROS) && !defined(UINT64_C)
#error missing -D__STDC_CONSTANT_MACROS / #define __STDC_CONSTANT_MACROS
#endif

#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <math.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "attributes.h"
#include "macros.h"
#include "version.h"
#include "libavutil/avconfig.h"

#if AV_HAVE_BIGENDIAN
#define AV_NE(be, le) (be)
#else
#define AV_NE(be, le) (le)
#endif

// rounded division & shift
#define RSHIFT(a, b) ((a) > 0 ? ((a) + ((1 << (b)) >> 1)) >> (b) : ((a) + ((1 << (b)) >> 1) - 1) >> (b))
/* assume b>0 */
#define ROUNDED_DIV(a, b) (((a) > 0 ? (a) + ((b) >> 1) : (a) - ((b) >> 1)) / (b))
/* Fast a/(1<<b) rounded toward +inf. Assume a>=0 and b>=0 */
#define AV_CEIL_RSHIFT(a, b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) : ((a) + (1 << (b)) - 1) >> (b))
/* Backwards compat. */
#define FF_CEIL_RSHIFT AV_CEIL_RSHIFT

#define FFUDIV(a, b) (((a) > 0 ? (a) : (a) - (b) + 1) / (b))
#define FFUMOD(a, b) ((a) - ( b )*FFUDIV(a, b))

/**
 * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they
 * are not representable as absolute values of their type. This is the same
 * as with *abs()
 * @see FFNABS()
 */
#define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
#define FFSIGN(a) ((a) > 0 ? 1 : -1)

/**
 * Negative Absolute value.
 * this works for all integers of all types.
 * As with many macros, this evaluates its argument twice, it thus must not have
 * a sideeffect, that is FFNABS(x++) has undefined behavior.
 */
#define FFNABS(a) ((a) <= 0 ? (a) : (-(a)))

/**
 * Comparator.
 * For two numerical expressions x and y, gives 1 if x > y, -1 if x < y, and 0
 * if x == y. This is useful for instance in a qsort comparator callback.
 * Furthermore, compilers are able to optimize this to branchless code, and
 * there is no risk of overflow with signed types.
 * As with many macros, this evaluates its argument multiple times, it thus
 * must not have a side-effect.
 */
#define FFDIFFSIGN(x, y) (((x) > (y)) - ((x) < (y)))

#define FFMAX(a, b) ((a) > (b) ? (a) : (b))
#define FFMAX3(a, b, c) FFMAX(FFMAX(a, b), c)
#define FFMIN(a, b) ((a) > (b) ? (b) : (a))
#define FFMIN3(a, b, c) FFMIN(FFMIN(a, b), c)

#define FFSWAP(type, a, b)        \
    do {                          \
        type SWAP_tmp = b;        \
        b             = a;        \
        a             = SWAP_tmp; \
    } while(0)
#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))

/* misc math functions */

#ifdef HAVE_AV_CONFIG_H
#include "config.h"
#include "intmath.h"
#endif

/* Pull in unguarded fallback defines at the end of this file. */
#include "common.h"

#ifndef av_log2
av_const int av_log2(unsigned v);
#endif

#ifndef av_log2_16bit
av_const int av_log2_16bit(unsigned v);
#endif

/**
 * Clip a signed integer value into the amin-amax range.
 * @param a value to clip
 * @param amin minimum value of the clip range
 * @param amax maximum value of the clip range
 * @return clipped value
 */
static av_always_inline av_const int av_clip_c(int a, int amin, int amax) {
#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
    if(amin > amax)
        abort();
#endif
    if(a < amin)
        return amin;
    else if(a > amax)
        return amax;
    else
        return a;
}

/**
 * Clip a signed 64bit integer value into the amin-amax range.
 * @param a value to clip
 * @param amin minimum value of the clip range
 * @param amax maximum value of the clip range
 * @return clipped value
 */
static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax) {
#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
    if(amin > amax)
        abort();
#endif
    if(a < amin)
        return amin;
    else if(a > amax)
        return amax;
    else
        return a;
}

/**
 * Clip a signed integer value into the 0-255 range.
 * @param a value to clip
 * @return clipped value
 */
static av_always_inline av_const uint8_t av_clip_uint8_c(int a) {
    if(a & (~0xFF))
        return (~a) >> 31;
    else
        return a;
}

/**
 * Clip a signed integer value into the -128,127 range.
 * @param a value to clip
 * @return clipped value
 */
static av_always_inline av_const int8_t av_clip_int8_c(int a) {
    if((a + 0x80U) & ~0xFF)
        return (a >> 31) ^ 0x7F;
    else
        return a;
}

/**
 * Clip a signed integer value into the 0-65535 range.
 * @param a value to clip
 * @return clipped value
 */
static av_always_inline av_const uint16_t av_clip_uint16_c(int a) {
    if(a & (~0xFFFF))
        return (~a) >> 31;
    else
        return a;
}

/**
 * Clip a signed integer value into the -32768,32767 range.
 * @param a value to clip
 * @return clipped value
 */
static av_always_inline av_const int16_t av_clip_int16_c(int a) {
    if((a + 0x8000U) & ~0xFFFF)
        return (a >> 31) ^ 0x7FFF;
    else
        return a;
}

/**
 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
 * @param a value to clip
 * @return clipped value
 */
static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a) {
    if((a + 0x80000000u) & ~UINT64_C(0xFFFFFFFF))
        return (int32_t)((a >> 63) ^ 0x7FFFFFFF);
    else
        return ( int32_t )a;
}

/**
 * Clip a signed integer into the -(2^p),(2^p-1) range.
 * @param  a value to clip
 * @param  p bit position to clip at
 * @return clipped value
 */
static av_always_inline av_const int av_clip_intp2_c(int a, int p) {
    if((( unsigned )a + (1 << p)) & ~((2 << p) - 1))
        return (a >> 31) ^ ((1 << p) - 1);
    else
        return a;
}

/**
 * Clip a signed integer to an unsigned power of two range.
 * @param  a value to clip
 * @param  p bit position to clip at
 * @return clipped value
 */
static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p) {
    if(a & ~((1 << p) - 1))
        return (~a) >> 31 & ((1 << p) - 1);
    else
        return a;
}

/**
 * Clear high bits from an unsigned integer starting with specific bit position
 * @param  a value to clip
 * @param  p bit position to clip at
 * @return clipped value
 */
static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p) {
    return a & ((1 << p) - 1);
}

/**
 * Add two signed 32-bit values with saturation.
 *
 * @param  a one value
 * @param  b another value
 * @return sum with signed saturation
 */
static av_always_inline int av_sat_add32_c(int a, int b) {
    return av_clipl_int32(( int64_t )a + b);
}

/**
 * Add a doubled value to another value with saturation at both stages.
 *
 * @param  a first value
 * @param  b value doubled and added to a
 * @return sum sat(a + sat(2*b)) with signed saturation
 */
static av_always_inline int av_sat_dadd32_c(int a, int b) {
    return av_sat_add32(a, av_sat_add32(b, b));
}

/**
 * Subtract two signed 32-bit values with saturation.
 *
 * @param  a one value
 * @param  b another value
 * @return difference with signed saturation
 */
static av_always_inline int av_sat_sub32_c(int a, int b) {
    return av_clipl_int32(( int64_t )a - b);
}

/**
 * Subtract a doubled value from another value with saturation at both stages.
 *
 * @param  a first value
 * @param  b value doubled and subtracted from a
 * @return difference sat(a - sat(2*b)) with signed saturation
 */
static av_always_inline int av_sat_dsub32_c(int a, int b) {
    return av_sat_sub32(a, av_sat_add32(b, b));
}

/**
 * Clip a float value into the amin-amax range.
 * @param a value to clip
 * @param amin minimum value of the clip range
 * @param amax maximum value of the clip range
 * @return clipped value
 */
static av_always_inline av_const float av_clipf_c(float a, float amin, float amax) {
#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
    if(amin > amax)
        abort();
#endif
    if(a < amin)
        return amin;
    else if(a > amax)
        return amax;
    else
        return a;
}

/**
 * Clip a double value into the amin-amax range.
 * @param a value to clip
 * @param amin minimum value of the clip range
 * @param amax maximum value of the clip range
 * @return clipped value
 */
static av_always_inline av_const double av_clipd_c(double a, double amin, double amax) {
#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
    if(amin > amax)
        abort();
#endif
    if(a < amin)
        return amin;
    else if(a > amax)
        return amax;
    else
        return a;
}

/** Compute ceil(log2(x)).
 * @param x value used to compute ceil(log2(x))
 * @return computed ceiling of log2(x)
 */
static av_always_inline av_const int av_ceil_log2_c(int x) {
    return av_log2((x - 1) << 1);
}

/**
 * Count number of bits set to one in x
 * @param x value to count bits of
 * @return the number of bits set to one in x
 */
static av_always_inline av_const int av_popcount_c(uint32_t x) {
    x -= (x >> 1) & 0x55555555;
    x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
    x = (x + (x >> 4)) & 0x0F0F0F0F;
    x += x >> 8;
    return (x + (x >> 16)) & 0x3F;
}

/**
 * Count number of bits set to one in x
 * @param x value to count bits of
 * @return the number of bits set to one in x
 */
static av_always_inline av_const int av_popcount64_c(uint64_t x) {
    return av_popcount(( uint32_t )x) + av_popcount((uint32_t)(x >> 32));
}

static av_always_inline av_const int av_parity_c(uint32_t v) {
    return av_popcount(v) & 1;
}

#define MKTAG(a, b, c, d) ((a) | ((b) << 8) | ((c) << 16) | (( unsigned )(d) << 24))
#define MKBETAG(a, b, c, d) ((d) | ((c) << 8) | ((b) << 16) | (( unsigned )(a) << 24))

/**
 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
 *
 * @param val      Output value, must be an lvalue of type uint32_t.
 * @param GET_BYTE Expression reading one byte from the input.
 *                 Evaluated up to 7 times (4 for the currently
 *                 assigned Unicode range).  With a memory buffer
 *                 input, this could be *ptr++.
 * @param ERROR    Expression to be evaluated on invalid input,
 *                 typically a goto statement.
 *
 * @warning ERROR should not contain a loop control statement which
 * could interact with the internal while loop, and should force an
 * exit from the macro code (e.g. through a goto or a return) in order
 * to prevent undefined results.
 */
#define GET_UTF8(val, GET_BYTE, ERROR)          \
    val = (GET_BYTE);                           \
    {                                           \
        uint32_t top = (val & 128) >> 1;        \
        if((val & 0xc0) == 0x80 || val >= 0xFE) \
            ERROR                               \
        while(val & top) {                      \
            int tmp = ( GET_BYTE )-128;         \
            if(tmp >> 6)                        \
                ERROR                           \
            val = (val << 6) + tmp;             \
            top <<= 5;                          \
        }                                       \
        val &= (top << 1) - 1;                  \
    }

/**
 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
 *
 * @param val       Output value, must be an lvalue of type uint32_t.
 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
 *                  to native byte order.  Evaluated one or two times.
 * @param ERROR     Expression to be evaluated on invalid input,
 *                  typically a goto statement.
 */
#define GET_UTF16(val, GET_16BIT, ERROR)    \
    val = GET_16BIT;                        \
    {                                       \
        unsigned int hi = val - 0xD800;     \
        if(hi < 0x800) {                    \
            val = GET_16BIT - 0xDC00;       \
            if(val > 0x3FFU || hi > 0x3FFU) \
                ERROR                       \
            val += (hi << 10) + 0x10000;    \
        }                                   \
    }

/**
 * @def PUT_UTF8(val, tmp, PUT_BYTE)
 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
 * @param val is an input-only argument and should be of type uint32_t. It holds
 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
 * val is given as a function it is executed only once.
 * @param tmp is a temporary variable and should be of type uint8_t. It
 * represents an intermediate value during conversion that is to be
 * output by PUT_BYTE.
 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
 * It could be a function or a statement, and uses tmp as the input byte.
 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
 * executed up to 4 times for values in the valid UTF-8 range and up to
 * 7 times in the general case, depending on the length of the converted
 * Unicode character.
 */
#define PUT_UTF8(val, tmp, PUT_BYTE)                        \
    {                                                       \
        int      bytes, shift;                              \
        uint32_t in = val;                                  \
        if(in < 0x80) {                                     \
            tmp = in;                                       \
            PUT_BYTE                                        \
        }                                                   \
        else {                                              \
            bytes = (av_log2(in) + 4) / 5;                  \
            shift = (bytes - 1) * 6;                        \
            tmp   = (256 - (256 >> bytes)) | (in >> shift); \
            PUT_BYTE                                        \
            while(shift >= 6) {                             \
                shift -= 6;                                 \
                tmp = 0x80 | ((in >> shift) & 0x3f);        \
                PUT_BYTE                                    \
            }                                               \
        }                                                   \
    }

/**
 * @def PUT_UTF16(val, tmp, PUT_16BIT)
 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
 * @param val is an input-only argument and should be of type uint32_t. It holds
 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
 * val is given as a function it is executed only once.
 * @param tmp is a temporary variable and should be of type uint16_t. It
 * represents an intermediate value during conversion that is to be
 * output by PUT_16BIT.
 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
 * in desired endianness. It could be a function or a statement, and uses tmp
 * as the input byte.  For example, PUT_BYTE could be "*output++ = tmp;"
 * PUT_BYTE will be executed 1 or 2 times depending on input character.
 */
#define PUT_UTF16(val, tmp, PUT_16BIT)               \
    {                                                \
        uint32_t in = val;                           \
        if(in < 0x10000) {                           \
            tmp = in;                                \
            PUT_16BIT                                \
        }                                            \
        else {                                       \
            tmp = 0xD800 | ((in - 0x10000) >> 10);   \
            PUT_16BIT                                \
            tmp = 0xDC00 | ((in - 0x10000) & 0x3FF); \
            PUT_16BIT                                \
        }                                            \
    }

#include "mem.h"

#ifdef HAVE_AV_CONFIG_H
#include "internal.h"
#endif /* HAVE_AV_CONFIG_H */

#endif /* AVUTIL_COMMON_H */

/*
 * The following definitions are outside the multiple inclusion guard
 * to ensure they are immediately available in intmath.h.
 */

#ifndef av_ceil_log2
#define av_ceil_log2 av_ceil_log2_c
#endif
#ifndef av_clip
#define av_clip av_clip_c
#endif
#ifndef av_clip64
#define av_clip64 av_clip64_c
#endif
#ifndef av_clip_uint8
#define av_clip_uint8 av_clip_uint8_c
#endif
#ifndef av_clip_int8
#define av_clip_int8 av_clip_int8_c
#endif
#ifndef av_clip_uint16
#define av_clip_uint16 av_clip_uint16_c
#endif
#ifndef av_clip_int16
#define av_clip_int16 av_clip_int16_c
#endif
#ifndef av_clipl_int32
#define av_clipl_int32 av_clipl_int32_c
#endif
#ifndef av_clip_intp2
#define av_clip_intp2 av_clip_intp2_c
#endif
#ifndef av_clip_uintp2
#define av_clip_uintp2 av_clip_uintp2_c
#endif
#ifndef av_mod_uintp2
#define av_mod_uintp2 av_mod_uintp2_c
#endif
#ifndef av_sat_add32
#define av_sat_add32 av_sat_add32_c
#endif
#ifndef av_sat_dadd32
#define av_sat_dadd32 av_sat_dadd32_c
#endif
#ifndef av_sat_sub32
#define av_sat_sub32 av_sat_sub32_c
#endif
#ifndef av_sat_dsub32
#define av_sat_dsub32 av_sat_dsub32_c
#endif
#ifndef av_clipf
#define av_clipf av_clipf_c
#endif
#ifndef av_clipd
#define av_clipd av_clipd_c
#endif
#ifndef av_popcount
#define av_popcount av_popcount_c
#endif
#ifndef av_popcount64
#define av_popcount64 av_popcount64_c
#endif
#ifndef av_parity
#define av_parity av_parity_c
#endif
